Autoantibodies to double stranded deoxyribose nucleic acid (dsDNA) are relatively specific for systemic lupus erythematosus (SLE) and are implicated in disease pathogenesis. Certain anti-DNA autoantibodies have been shown to penetrate cells and localize to the cell nucleus. Cellular penetration by anti-DNA antibodies was initially demonstrated in peripheral blood T-lymphocytes (see, for example, Okudaira, et al., in Arthritis Rheum. 30:669 (1987) and Alarcon-Segovia, et al., in Clin. exp. Immunol. 35:364 (1979)) and, subsequently, was shown to affect their function (see, for example, Okudaira, et al., supra, Alarcon-Segovia, et al., in J. Immunol. 122:1855 (1979), Alarcon-Segovia, et al., in Clin. Immunol. Immunopath. 23:22 (1982), Alarcon-Segovia and Llorente in Clin. exp. Immunol. 52:365 (1983), and Alarcon-Segovia, in Clinics in Immunology and Allergy 1:117 (1981)).
In some studies, antibody penetration was thought to be mediated by Fc receptors (see, for example, Llerena, et al., in Immunology 43:249 (1981) and Alarcon-Segovia, et al., in Nature 271:67 (1978)). For other anti-DNA antibodies, cellular penetration and translocation to the cell nucleus was thought to require the presence of DNA (see, for example, Okudaira, et al., supra). More recently, penetration of anti-DNA antibodies has been demonstrated in mesangial cells (Vlahakos, et al., in T. Am. Soc. Nephrol. 2(8):1345 (1992)). Anti-DNA antibodies have been shown to enter the nucleus of cultured mesangial and hepatoma cells in a time and temperature dependent manner (Yanase, et al., in Lab. Invest. 71:52 (1994).
There are multiple mechanisms by which anti-DNA antibodies are thought to penetrate cells. Indeed, different antibodies may use different pathways. Since some anti-DNA antibodies have been shown to bind membrane proteins cross reactive with DNA, these proteins may be instrumental in cellular penetration (see, for example, Brentjens and Andres in Kidney International 35:954 (1989), Raz, et al., J. Immunol. 142:3076 (1989), Madaio, et al., in J. Immunol. 138:2883 (1987), Faaber, et al., in J. Clin. Invest. 77:1824 (1986), Ben-Chetrit, et al., in Clin. exp. Immunol. 60:159 (1985), Jacob, et al., in Proc. Natl. Acad. Sci. USA 81:3843 (1984), Jacob, et al., in Proc. Natl. Acad. Sci. USA 86:4669.4669 (1989), Raz, et al., in Eur. J. Immunol. 23:383.383 (1993), and Jacob, et al., in J. Clin. Invest. 75:315 (1985)). In other cases, DNA binding proteins usually thought of as intracellular have been described in association with the membrane of some cells (see, for example, Bennett, et al., in J. Clin. Invest. 76:2182 (1985) and Refeneider, et al., in Clin. Immunol. Immunopath. 63:245 (1992)). Anti-DNA antibodies could form complexes with these proteins through their mutual binding to DNA.
For additional background information, see U.S. Pat. No. 4,812,397 and “DNA Mimics a Self-Protein That May Be a Target for Some Anti-DNA Antibodies in Systemic Lupus Erythematosus”, Journal Of Immunology, pages 1987–1994 (Feb. 15, 1995), the contents of each of which are hereby incorporated by reference in their entirety.
Mutations in the p53 tumor suppressor protein are a frequent cause of cancer. Methods to regulate and restore the function of p53 are promising approaches to the treatment of cancer. Restoring p53 function by delivering functional p53 into cancer cells and delivering p53 peptides have been investigated in several studies. Various delivery vehicles have been used to deliver p53 and p53 peptides into cancer cells for restoration of p53 function. These include VP 22, a herpes simplex virus 1 protein (15,16), and the third alpha helix of Antennapedia homeodomain (8). The potential disadvantage of these vectors is that they are foreign proteins that may be immunogenic in humans.
In view of the availability of antibodies which are capable of penetrating cells, it would be desirable to selectively utilize such cell penetrating properties for the directed manipulation of biological materials.